CVE-2026-40969: Spring Framework Spring GRPC AuthenticationException Messages Are Vulnerability

LOW
Advisory Identifier: GHSA-37w2-q6vh-45v6
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CVSS 3.7
CWE-209
Published
Advisory Summary

CVE-2026-40969 is a LOW (CVSS 3.7) spring grpc authenticationexception messages are vulnerability (CWE-209: Generation of Error Message Containing Sensitive Information) affecting Spring Framework libraries in the Maven ecosystem. The issue involves spring grpc authenticationexception messages are reflected to remote client. Remediation is available by upgrading affected packages to version 1.0.3.

CVE-2026-40969 at a Glance

CVE Identifier CVE-2026-40969
GHSA Identifier GHSA-37w2-q6vh-45v6
Severity LOW
CVSS v3.1 Base Score 3.7
CWE Classification CWE-209: Generation of Error Message Containing Sensitive Information
Affected Product Spring Framework
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 3.7

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N).

Attack Vector Network (AV:N)
Attack Complexity High (AC:H)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality Low (C:L)
Integrity None (I:N)
Availability None (A:N)

How to Fix CVE-2026-40969

To remediate this vulnerability, upgrade all affected Spring Framework dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

org.springframework.grpc:spring-grpc fixed: 1.0.3 
<dependency>
    <groupId>org.springframework.grpc</groupId>
    <artifactId>spring-grpc</artifactId>
    <version>1.0.3</version>
</dependency>
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

mvn dependency:tree -Dincludes=org.springframework.grpc

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2026-40969, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree -Dincludes=org.springframework.grpc

Analyze the terminal output to locate any version of Spring Framework in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.0.3), your application is affected.

Note: The mvn dependency:tree -Dincludes=org.springframework.grpc command inspects the resolved dependency graph declared in your project's POM files; it does not perform automated security scanning or inspect runtime dynamic classpaths. Always verify runtime container classpaths and shaded JARs.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-209: Generation of Error Message Containing Sensitive Information, where the product generates an error message that includes sensitive information about its environment, users, or associated data. In Spring Framework, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

The raw message of every server-side AuthenticationException is returned to the unauthenticated remote caller in the gRPC status description. This allows an attacker to obtain information about the authentication failure, which may be useful for further attacks. Affected versions: Spring gRPC: 1.0.0 - 1.0.2 (fixed in 1.0.3). Older, unsupported versions are also affected.

CVE-2026-40969 Affected Spring Framework Versions

1 component(s)
Fixed Versions:
1.0.3
Product / Package Ecosystem Affected Versions Fixed Version
org.springframework.grpc:spring-grpc
maven/org.springframework.grpc/spring-grpc
Maven
< 1.0.3
1.0.3

References

NVD — CVE-2026-40969 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-40969
Spring Framework Source Repository REPOSITORY
https://github.com/spring-projects/spring-grpc
Spring Framework Security Information SECURITY
https://spring.io/security/cve-2026-40969

Frequently Asked Questions

What is CVE-2026-40969?
CVE-2026-40969 is a security vulnerability in Spring Framework involving Spring gRPC AuthenticationException messages are reflected to remote client under CWE-209: Generation of Error Message Containing Sensitive Information.
Which Spring Framework versions are affected?
Affected versions include releases prior to 1.0.3 across affected packages: org.springframework.grpc:spring-grpc.
What version fixes CVE-2026-40969?
Upgrading to 1.0.3 (or the latest patched release for your respective branch) resolves the vulnerability.
Is spring-grpc affected?
Yes, org.springframework.grpc:spring-grpc is affected in releases prior to 1.0.3. Upgrade your dependency to 1.0.3 or later.
What is the CVSS score of CVE-2026-40969?
CVE-2026-40969 has a CVSS v3.1 base score of 3.7 (LOW) with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N.
What CWE is associated with CVE-2026-40969?
CVE-2026-40969 is classified under CWE-209: Generation of Error Message Containing Sensitive Information (The product generates an error message that includes sensitive information about its environment, users, or associated data.).
How can I check Maven dependencies for CVE-2026-40969?
Run the dependency tree command: 'mvn dependency:tree -Dincludes=org.springframework.grpc'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-37w2-q6vh-45v6",
  "modified" : "2026-05-06T20:00:01Z",
  "published" : "2026-04-28T15:30:51Z",
  "aliases" : [ "CVE-2026-40969" ],
  "summary" : "Spring gRPC AuthenticationException messages are reflected to remote client",
  "details" : "The raw message of every server-side AuthenticationException is returned to the unauthenticated remote caller in the gRPC status description. This allows an attacker to obtain information about the authentication failure, which may be useful for further attacks.\n\nAffected versions:\nSpring gRPC: 1.0.0 - 1.0.2 (fixed in 1.0.3). Older, unsupported versions are also affected.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.springframework.grpc:spring-grpc"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.0.3"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-40969"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/spring-projects/spring-grpc"
  }, {
    "type" : "WEB",
    "url" : "https://spring.io/security/cve-2026-40969"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-209" ],
    "severity" : "LOW",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-05-06T20:00:01Z",
    "nvd_published_at" : "2026-04-28T15:16:30Z"
  }
}